The Best Logique Evidence of God Existence

[Belacqua]

And I see the problem as assuming there is a *cause* for everything to exist. Since, for example, any cause must exist prior to causing anything else to exist, there is ultimately no cause for why things exist.

The Aristotelian/Thomist argument uses "prior" in an essential way, not a temporal way.

It would be clearer to get rid of the modern English word "cause" and write it like this: "Everything that exists requires that something else is the case -- right now -- in order to exist." 

As an example we could talk about human life. Human life requires, among many other things, the warmth of the sun. If the warmth of the sun suddenly disappeared, we would freeze and there would be no more human life. 

It's true that the sun existed before people, but that's not crucial to this essential chain. We say that the warmth of the sun is "prior," in this case, because if it stopped people would stop. But if people stopped, the warmth of the sun wouldn't stop. That's essential priority. 

The warmth of the sun depends for its existence on the sun. The sun depends for its existence on hydrogen atoms. 

So hydrogen atoms are essentially prior, because if they disappeared the sun would disappear. But if the sun disappeared, there would still be lots of other hydrogen atoms, elsewhere. 

The hydrogen atoms depend for their existence on space-time. Even if hydrogen and space-time appeared together, we would still say that space-time is essentially prior, because if it disappeared hydrogen would disappear too. But if hydrogen disappeared, we'd still have space-time. 

I don't know if the OP is aware of this, or if he's arguing the temporal Kalam argument. But traditional First Cause arguments are not about time.